SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf32c44cc20701f59258b52ce2d13b58cee7475d0c92aa252efcfdf3179a95e6' 
  AND token = 'LnbrekOKzz+8rdTOvpn6ZNqgqBcV+Y8HLLux1dFTJyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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