SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e7d631b0f6411debfc0cc724833eff91cef701cb72ebf17e6465e91ca64e992' 
  AND token = 'BHkl3F/ndRLArN4/2oYdQdyjdfrKwYh4uzX0kUmIunk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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