SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a83be0e57fcc1590a7659140259f163dca43e107bc19ed7bd308935bcdca51fc' 
  AND token = 'wgX38w0lqwe1qQoGJCFzYYthPw/6HNH+jqJ/JNPwkeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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