SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5026381fd25375e0ad79d1db72148d72f62d6af0d57e23afa1f1ae5cd4a8f6f9' 
  AND token = 'ZrVgzaHrroCW4JLvt884/nPi+Zr7oViz65Y0QebBo74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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