SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6d64239c3997429b637b1c39be086689203edd01197530a108f9a0ff522c704' 
  AND token = 'MeLswIdCu6h1cGwl+2jOfHjAD+xioNtmrhurogaDTz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}