SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b14759f6a8dfe6fa31c3cbe3e91c66be03ea8cb73f5e705c59756cd82be56190' 
  AND token = 'qyuHCMjneyQpbgd8k57COzcw/+hUz6lUwjGue0BX288=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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