SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d3d88093d48ad3083ba5aded368daad3dfe4fa71ca5360512e6dfa90632fa26' 
  AND token = '27ZqFxXILdMinjGsZUTBgwR1dj2rOT2LWNcLjVJBhNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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