SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffee4beac3400c934dc5832cd8d3f6b57c005787a9e81d01a50a4a82f26998c3' 
  AND token = 'Y//lKPPjDWqmSuFgL98EFKjF6bZy+Ac33B2iYO4JX9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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