SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cce065018db577fc03502f413d6434c88134831493de3e29fb133cb2839f409b' 
  AND token = 'cZZwoLoXus9laeaGM1r7B1RpQ3Eb7lYSgvWifUAg2Bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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