SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '51cbbe2ed077df7fcadf00db6bead86db96e83d905aad5cb5feff42c345a9e8d' 
  AND token = 'cNzZUYLqaCGIUF0JAOgrbUbULhtPlxwygVm6W3dVlro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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