SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acdd9fcbd325c93a69fb0a222d399449e11f99ac10d7ef01c8d2e38cc55d6f0b' 
  AND token = 'LNxLrXKRPvq633qzWtM+I55IPp2SzcNkAaIVkuTfDBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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