SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fed0f809ebf2d4778cb06efebaf0a755bd27739957c44c4a5d4fc2379af26566' 
  AND token = 'Tij6P12N3IoWmuZ8FcBYT4d981hB2FSu/eTI6q6gg7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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