SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bca854362fabc3740f49383fe7595d51d9c05276e97eda81c1cf100e1265f18' 
  AND token = '4g8VJu7OwDNDoNsRIaLipizlBrfZYKIknE5dAET4fvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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