SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97d0f444bb73c0c867a048ffb5a2d8e6318b79db61334fa2106a05cbc5f252e9' 
  AND token = 'GDUS+cR4ZIpGVlJeHD1MEzDvsG+/Dzy4Vw7xGQ0Gx+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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