SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0af7db189f583950daaa927f50a6a5111991609e5c3609ad810cca0bfe35808' 
  AND token = 'aeU0DE8QlBiH5pKDRDVveYgqR6aRz7LodPYHy4UDIps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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