SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1d482a1a56583490f9266466014db73ab249bb747bd45e95291b19a56cdfc4b' 
  AND token = 'c4ceqiWguSCjiPm/BCqr0Cy6wUXnB6NC/igsal6CTFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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