SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2403743cf24f63b1680ec5d6e6f83c579fc9abb3657e44150a05c5d12ec27ce1' 
  AND token = 'WDBq33DfsIY/g4Mtg/+KUq+8ZoXBd55vKg0bnZVgODE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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