SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3cd4beeee27b37a0aa73c1f6f6cda61f7460cf209c7186c5f8536a603f191f5' 
  AND token = 'bmlixfpoekK9QGwSOTgBfBMcCDLf/pXz/f4xgPnXiSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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