SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb57a374d2f34247655d973692e3ced17c5996cf66c65ee3e73058dfca93c0a5' 
  AND token = '8dfWkf5tKSCPKm9CsJyDNmOFqylyZtaWdyHXXWjADRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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