SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12993eb2af906b12e89765f3417ce82598a7a8d53f5a2b81e55bf4cc7be0cc3d' 
  AND token = 'd/gqgWDty6YONPSodEGBZTXaoU8IewqwPSKsI+CsKVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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