SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f827b23ec2edda0c10251dea629060a90dd96603f335f4170cd62ed42e069fb' 
  AND token = 'Q0FYkYO/MI/T0nx2Vlh/oxgq+fiVrM4zbydDl9lqXTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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