SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b09e2dc53e1d0792beb421648d230aa80a954d40cf4295ea2ee016f995b58660' 
  AND token = 'f+IfDR/Qc/aB20zS+RN+4jd+K5yPAWnIFY9g8ZFwh3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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