SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91652edbb46bc3bd0c944057826af34bcd531d225eb4b480ed2a4cb9c2ef83ab' 
  AND token = 'I+Sv924Hibwrxgk3xLUCR/qd7qQV+ZJuJGYIvHit2P4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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