SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '124729997424efdd695550b7cdeae7fc58e74adda3510ca5266424b00166491c' 
  AND token = 'eo6LDV/d2Zo71zb5CKNFMTiYMwcbLCZV6HkmfEg78UU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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