SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '071d44b0287a3acea82043bc6214bd09c584bfac0384bb03168fe1903b97c3c7' 
  AND token = 'dsvIBMvHgLQDjGj43j72rTKZIKSnoheT04MNpxBs3Gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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