SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c87730d732cfd9d7eaa9b4c75a07a63ef46c275a5fc294c15523090b057750c3' 
  AND token = 'BmQBF1hgLSG+rGOgwpX4VVxGmxMRZ+Gza5RF+kzndOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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