SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a0a8467af280ae11cba646d5604e8ef7da6f73bf6498874c1d85056e2fded64' 
  AND token = 'Ysu/0WaOKwmtGC/PAoKZSHSg3U+9LkXhQVih7el42cE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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