SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b8f3a9790fd11a885e5d517e32e98f953d9c4600f40b65706ef4ead6ffd7a2a' 
  AND token = 'qJiVjmNsFKP6T4yTHwyaB502syutcdTTcdBDwmExMBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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