SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fc6e24be88284c3dcc3f831946ff5c8f9e312f1a850b28fa563b617dc7f4c90' 
  AND token = 'KXacP6+4K5bFkdRJZ1m4+ovwPgq/6jPfsW6hpQ8X6/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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