SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '508da66a537f76655270d2a86a69460a610d609f9ff2d7c6cb87fec48fc38d9f' 
  AND token = 'GS34nLUEn6A6vAUanVpzhgS1Ak5y+ETTrIfAQ4QeJ60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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