SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df7d3d1aabfaf675a0ded2d9394be5763584b933044765417608dc3293d37109' 
  AND token = 'ITGIzi8CfeVT3L6gcPj0BDKLBEtSYlH+hJEvK+n7ZVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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