SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04f126789b4c64746ecdd0f44ce774046eae55c6e7688ade095ec2bd584ad473' 
  AND token = 'az6AQLM/65pxJr6yUdaEhfVlpM3pyiOem1vQAKQCrHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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