SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd77d64c3b38b6af951b0bbb4b726cdf078eabbb03a3dbeaf3c2fa385ab6b22ce' 
  AND token = 'BzIkmLJaBISmUXuH2xqGJ5BhMWSa779anMw6xfiG5SQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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