SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '716e8f3311bb644b38e7e4490ac6e9b6db336385b5bc9d8d71fca128ee76ac55' 
  AND token = 'T+NwObSXRI8M6y2MPQ2RW8KA7FMgnTYozmVONfOK/LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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