SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '625abf18c5255b6a637d1db0acbd0c98b3d3d6fd1ab0511f7ce4fce6a6280044' 
  AND token = 'uh8cLEdet55A1+4O5mzq2NDAh29aWl7zrmnehxNLtiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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