SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38bc0014cecb942dedab5a5d60166bc70d2d7d775cb022eb71a2588aeb8036be' 
  AND token = '9sm1ScpWN2nIIWP8kR9zxBBL4jLt8+f1De1Plae1UOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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