SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d4b1edcb0fd21ec2d5b7596dd757a813aef077684443630c95e23cf15576fbc' 
  AND token = 'kvYbKZh9V6PtOvNDzg6T2NcuwAnuTzu2wZAV+HeuXsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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