SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fb13db1a29d291d3daa4330e79b0e7e16becb46b368cf3ea07da197f0325061' 
  AND token = 'hhNY3td7uih1fgHS22vYSd4DRUFYUxcvZ2qF+mMP4cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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