SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36d98e17f72a80e6e76f497dc29602a309a5c28573ae85b11eb3b22a98706e36' 
  AND token = 'Y5EzF6M+LLlJorGAVaAF5PGOFgePHNw4TIQfmtRjpMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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