SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a90a03ff9f84f45482bfaf325c73294d9125a62725148aa2095ced36de29c163' 
  AND token = '8JKsFZuKYHwAYtsjjCD7qGFv5OImcjkzsKfnlzyzlhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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