SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '214bfd8abdf22dee94cd85710178ff03aa90a958fd37e97fa19101e9b17b172e' 
  AND token = 'phuKp88GAhTEDjFL8zALR16ZcxeDc3j9SZZEwqAi1TU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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