SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b65c0cda099350e74470159fe374cae15cf3689d18d08457fb14dd4fbdac125c' 
  AND token = 'MToZ5+rDHQU+LtxODLQwKjXdjbZm+iteA7dmmCWLCpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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