SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ec10afc7546f7e701692c8afaf1d0d7f79286b58740e9ede9a61ff47dc40691' 
  AND token = 'asLkDSeDJ9U0CRt3wORq/uOLy2sWYcOTxKpb/CG0wws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}