SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0cc082f40b3855597694323a06d06fc8ca5eb7705b34c3aa2954cbd30ed6175' 
  AND token = 'vKNGOtByRCHV9T9yELGzly8T2m+UTTsZgzOIU7q2LJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}