SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae83207526b532c2d2ea3054ae9b69840e9f4ec431f6395c8261be2a45059c0d' 
  AND token = 'muqpPIeufAzBBoQcaPn6GIGiDnQEu1Ud2z1Fwt+FOYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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