SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcaff2d7aaef316713e6fc551ba4a638535e146ce544a175e2924fe1a163193a' 
  AND token = 'YY4SluSXZtqon1kvnq5oofr9BXGWcEe6/YAKyl4HQUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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