SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3e097a3edd93007eebce0276590fb4b385dfbe859309c0dde4f551a139a5716' 
  AND token = 'YZ9oXy2xQj6vamtVbm1kRNZqlgiCq8GmF4Zm75dmh8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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