SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb5c14938b94c43e7bfafb313729f329391ea0a53df950f1fca4bc9563314320' 
  AND token = 'ERs6LOTzKkAZY5vBIYjqJalFDV05FDoxJSgnJpGBjDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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