SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59649416b2a1df3b8b772d3904f0c7aa821bc8c1ec583ef47fc744f7c3b24db6' 
  AND token = 'SnBV1bLAiOKTRfHYQgdPxZAswIeev4NulGZIl82KG4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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