SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8beb5efcfd37a39d1d7750c05ffe67af34e75c0f31387cd37dfa115547f54293' 
  AND token = 'LuFA6IRux30pYDvjw3EUnigo6I8WPywVHsGXK/II6GY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00071

JSON explain

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