SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '488e4c6a1c0b85016b0cb37c499e64e55acbe2754c899f95d1835b801effc3ef' 
  AND token = 'IaPi0jWe9xvfIwxEi83WRox6c2hcvrS96fSlBOFSFtQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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