SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4561e5d0eddc7113dea3e0370a752c7ad9a843a4459ab49b256f0daa632057fb' 
  AND token = 'KrHLpqpKbyh3loi03XlY8U2MtOwgtqN3Avm8ypQpdPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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