SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0b5640d1e4834046181a8748a76c985b0f3d79f224850195fa16ffd9816ead5c' 
  AND token = '/9NIDAthvXKPuGKaEdXNdPr22KUXc5rDszxLugmU+HU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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