SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59cd88558b90322b4b8168f046b176a4670df1e566eb6ebea8f6b06092d3dbd7' 
  AND token = 'E1DaCKsSKNKVknck3ztzOGNw43NrHLuAswIlJL6/eYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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