SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de17fbc8bccec9f2f97ee5f9fa1c4c36e395980688affef73c0a371eb4dcf4f0' 
  AND token = 'qzHXT4stC3RXLGGVqRHRJyboCBLuHMD8b3VGZaUtk8U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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