SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40b9b663555b47f63068e09aacdd746c83f959736bd6ad32a1272719b563ba28' 
  AND token = '57TZ9D4E13u1WOy5SlwsYp8s2K5+O4jmudaJTRcrMHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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