SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd86809a2654151b37cafcb05627d134f2c5db1afd94c66a5fd9d8150d4b28b5' 
  AND token = 'hUgdqokelT3ni8tnUv9pUR7USxzTCWR2C5x5g4apa5s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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