SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17e97508b4088bad1bfba3584e7081bed6fb8c24b94221690f4e6ded0512f8f4' 
  AND token = '2/8YZuFTTcv3fKkUI1l/IppRVu7/MJr2gjB+Vmk8KJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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