SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '278f397d4c97090770ce58e555ace6365ac52b0727cd95cd88941cf34f855a03' 
  AND token = 'ctqlyLYSxzOkSXZAhZV0OGu/kH/Y6L9cuAaFdzRe6js=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}