SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbf6e012c442d37bbccd1c042e2c45313357157f1c4eb98297a77b83e939c34a' 
  AND token = 'zxov9D0r+3uIpQ/Vpo9jhvScxZ86301JpGwVghN0RtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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